Question

Hydrocephaly or an accumulation of cerebrospinal fluid what most likely eventually result since the tumor would prevent normal movement and uptake of the liquid?

Answer 1

When CSF production is in excess of the CSF absorption, there will be accumulation of CSF inside the ventricle and subarachnoid space resulting in the Intracranial pressure.

Etiology:

• Overproduction of CSF
• Increased resistance to CSF flow
• Reduced absorpton of CSF
• Increased pressure in the dural sinuses.

This will cause:

1. Absorption of CSF by optic nerve roots causing enlargement of the optic nerve.- Known as 'Papilledema'
2. Dilation of lateral ventricles resulting in elevation of corpus callosum,stretching and perforation of septum pellucidum and thinning of the cerebral cortex.
3. Enlargement of the 3rd ventricle causing pituitary dysfunction, compression of the midbrain
4. Due to the raised intracranial pressure, some parts of brain may get herniated.

Signs and symptoms:

Infants;

• Head enlargement
• Poor feeding
• Irritability
• Reduced activity
• Vomiting

Children and Adults:

• Slowing of mental capacity
• Headache
• Neck pain- Tonsullar herniation
• Vomiting
• Blurred vision- Papilledema
• Double vision- 6th nerve palsy
• DrowsinessLimb spasticity & difficulty in walking - Stretching of the pyramidal and periventricular tracts.

4 Types :

1. Normal pressure hydrocephalus (NPH)
2. Communicating hydrocephalus
3. Non communicating hydrocephalus
4. Congenital hydrocephalus

1.Normal pressure hydrocephalus (NPH)

• Rare,
• Occurs in elderly people
• Enlarged ventricles - Normal ICP
• No papilledema
• Some patients - Increased ICP at night

Pathophysiology:

Mechanism – Poorly understood

Resistance to the CSF flow-----Raised ICP at night--------Stretching of ventricular walls----------Enlargement of ventricles

2.Communicating hydrocephalus

• Normal flow between the ventricles & Subarachnoid space
• Due to, Defective absorption of CSF Overproduction of CSF(rarely)

Causes :

• Intracranial hemorrhage
• Meningitis ·
• Brain tumors
• Venous thrombosis – Venous drainage insufficiency

Pathophysiology:

Accumulation of CSF in Subarachnoid space---------Atrophy of surrounding brain tissue, deep white matter structures-----------Crowding of sulci

3.Non Communicating hydrocephalus

• CSF flow obstruction
• Ventricular system Outlets - foramen of Luschka / Magendie

Pathophysiology:

Mass occupying lesions---------Disrupt ventricular anatomy------------Accumulation of CSF---------------Enlargement of ventricles

4.Congenital hydrocephalus

• Dilation of ventricles during fetal/infancy period

Causes :

• Obstruction of cerebral aqueduct
• Chiari malformation
• Premature births - Bleeding into the brain
• Dandy Walker malformation